It's the million-dollar question, right? One of the first phrases I learned when we started trying to conceive (TTC) was the “The Two Week Wait”. It’s the two weeks between ovulation and your expected period that you must wait before finding out if you are pregnant or not. In the TTC community, this wait can be brutal; especially if you’ve been trying for a while or have experienced a loss. When I started my TTC journey, I found that there were message boards and Youtube series devoted to tracking symptoms and interpreting tests. Some women shared testimonies of getting a “big fat positive” on day 7 DPO (days past ovulation), a full week before a missed period. This led me to feel anxious and to wonder, how soon is too soon to test?
How tests work
It’s important to first explain how pregnancy tests work. There are two main types of pregnancy tests: urine tests and blood tests. Both tests detect HCG levels in the body. HCG, or human chorionic gonadotropin, is a hormone secreted during pregnancy which stimulates continued production of progesterone. Shortly after the egg is fertilized, the body begins to produce HCG in order to alert the body to continue to produce hormones necessary to sustain pregnancy. HCG levels rise rapidly as the pregnancy progresses, doubling every 48-72 hours until they reach a plateau between 8 and 11 weeks of pregnancy.
Most home pregnancy tests react to the level of HCG present in urine. The sensitivity of each test varies depending on the brand. However, most tests can detect the presence of HCG in urine about 12-14 days after conception, which is right around the time of a missed period. Blood tests have a higher sensitivity and can detect pregnancy earlier than most home pregnancy tests. They are usually performed by doctors in a clinical setting and are typically performed after a urine test (usually if those results are unclear).
Since most women will be using home pregnancy tests in the first few weeks, we will focus on those.
What the internet says?
As I mentioned earlier, when I went to the online message boards and Facebook groups, I found that “when to test” was highly variable but a percentage of women got positive pregnancy test results several days before their expected period. I found that the vast majority of women had more success (more accurate results) the closer they got to their period (e.g. 11-14 DPO). Some women mentioned more success early on with pink dye tests while others mentioned avoiding digital pregnancy tests completely in the early stages because of their low sensitivity. The experience is varied and extremely dependent on every individual’s body. At the end of the day, it is all dependent on how quickly HCG levels reach threshold for the test to accurately detect it.
Most healthcare professionals recommend waiting until your missed period to take a pregnancy test for the most accurate results. This is because you want to give your body enough time to produce detectable HCG concentrations. All tests have a “threshold” in which they will show a positive result based on the level of HCG. Most tests will display a positive result with an HCG level of 25mIU/ML or greater. Some brands, like First Response, claim to have a higher sensitivity than other brands so it’s possible that their threshold is lower. The best way to avoid confusion is to wait until your body has had enough time to build up HCG. When I was waiting to test, I found viewing this chart from American Pregnancy helpful for understanding how HCG increases in the body.
The First Response Early Result pregnancy test markets itself as being one of the most sensitive tests on the market. Their tests instructions state that the test is 76% accurate 5 days away from missed period, 96% accuracy 4 days away, and 99% by 3 days out. Five days before your missed period is still more than a week after you ovulate! I know what it feels like to wait to find out about such a life-changing event. But, it is truly best to wait until your body has time to build-up enough HCG to be detectable on a pregnancy test. Testing too early can lead to false-negatives and unnecessary disappointment for the anxious future mama. Hang in there!